package manage.commons.utils;

import java.security.MessageDigest;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

import manage.commons.Constants;

import org.apache.commons.codec.binary.Base64;

/**
 * 加密解密工具类
 * 
 * @since 2012-07-09
 * @author dongji
 * 
 */
public class EncryptUtils {
	private static byte SECRETKEY[];
	private static final char hexDigits[] = { '0', '1', '2', '3', '4', '5',
			'6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
	private static final String PASSWORD_CRYPT_KEY = "@Gkdjw^3z";
	private final static String DES = "DES";

	/**
	 * 加密
	 * 
	 * @param src
	 *            数据源
	 * @param key
	 *            密钥，长度必须是8的倍数
	 * @return 返回加密后的数据
	 * @throws Exception
	 */
	public static byte[] encrypt(byte[] src, byte[] key) throws Exception {
		// DES算法要求有一个可信任的随机数源
		SecureRandom sr = new SecureRandom();
		// 从原始密匙数据创建DESKeySpec对象
		DESKeySpec dks = new DESKeySpec(key);
		// 创建一个密匙工厂，然后用它把DESKeySpec转换成
		// 一个SecretKey对象
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
		SecretKey securekey = keyFactory.generateSecret(dks);
		// Cipher对象实际完成加密操作
		Cipher cipher = Cipher.getInstance(DES);
		// 用密匙初始化Cipher对象
		cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);
		// 现在，获取数据并加密
		// 正式执行加密操作
		return cipher.doFinal(src);
	}

	/**
	 * 解密
	 * 
	 * @param src
	 *            数据源
	 * @param key
	 *            密钥，长度必须是8的倍数
	 * @return 返回解密后的原始数据
	 * @throws Exception
	 */
	public static byte[] decrypt(byte[] src, byte[] key) throws Exception {
		// DES算法要求有一个可信任的随机数源
		SecureRandom sr = new SecureRandom();
		// 从原始密匙数据创建一个DESKeySpec对象
		DESKeySpec dks = new DESKeySpec(key);
		// 创建一个密匙工厂，然后用它把DESKeySpec对象转换成
		// 一个SecretKey对象
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
		SecretKey securekey = keyFactory.generateSecret(dks);
		// Cipher对象实际完成解密操作
		Cipher cipher = Cipher.getInstance(DES);
		// 用密匙初始化Cipher对象
		cipher.init(Cipher.DECRYPT_MODE, securekey, sr);
		// 现在，获取数据并解密
		// 正式执行解密操作
		return cipher.doFinal(src);
	}

	/**
	 * 密码解密
	 * 
	 * @param data
	 * @return
	 * @throws Exception
	 */
	public final static String decrypt(String data) {
		try {
			return new String(decrypt(hex2byte(data.getBytes()),
					PASSWORD_CRYPT_KEY.getBytes()));
		} catch (Exception e) {
		}
		return null;
	}

	/**
	 * 密码加密
	 * 
	 * @param password
	 * @return
	 * @throws Exception
	 */
	public final static String encrypt(String password) {
		try {
			String strc = password;
			strc = new String(strc.getBytes("utf-8"));
			return byte2hex(encrypt(password.getBytes(),
					PASSWORD_CRYPT_KEY.getBytes()));
		} catch (Exception e) {
		}
		return null;
	}

	public static String byte2hex(byte[] b) {
		String hs = "";
		String stmp = "";
		for (int n = 0; n < b.length; n++) {
			stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
			if (stmp.length() == 1)
				hs = hs + "0" + stmp;
			else
				hs = hs + stmp;
		}
		return hs.toUpperCase();
	}

	public static byte[] hex2byte(byte[] b) {
		if ((b.length % 2) != 0)
			throw new IllegalArgumentException("长度不是偶数");
		byte[] b2 = new byte[b.length / 2];
		for (int n = 0; n < b.length; n += 2) {
			String item = new String(b, n, 2);
			b2[n / 2] = (byte) Integer.parseInt(item, 16);
		}
		return b2;
	}

	/**
	 * @description DES加密
	 * @param key
	 *            密钥
	 * @param data
	 *            明文数据
	 * @return
	 */
	public static String encryptDES(String key, String data) {
		try {
			SECRETKEY = key.getBytes();
			DESKeySpec dks = new DESKeySpec(SECRETKEY);
			SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
			SecretKey securekey = keyFactory.generateSecret(dks);
			IvParameterSpec spec = new IvParameterSpec(SECRETKEY);
			Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
			cipher.init(Cipher.ENCRYPT_MODE, securekey, spec);
			byte dest[] = cipher.doFinal(data.getBytes());
			return Base64.encodeBase64String(dest);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * @description DES解密
	 * @param key
	 *            密钥
	 * @param data
	 *            密文数据
	 * @return
	 */
	public static String decryptDES(String key, String data) {
		try {
			SECRETKEY = key.getBytes();
			DESKeySpec dks = new DESKeySpec(SECRETKEY);
			SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
			javax.crypto.SecretKey securekey = keyFactory.generateSecret(dks);
			IvParameterSpec spec = new IvParameterSpec(SECRETKEY);
			Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
			cipher.init(Cipher.DECRYPT_MODE, securekey, spec);
			byte buf[] = Base64.decodeBase64(data);
			byte dest[] = cipher.doFinal(buf);
			return new String(dest);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * @description MD5加密
	 * @param data
	 *            明文数据
	 * @return
	 */
	public static final String encryptMD5(String data) {
		try {
			byte[] strTemp = data.getBytes();
			MessageDigest messageDigest = MessageDigest.getInstance("MD5");
			messageDigest.update(strTemp);
			byte[] md = messageDigest.digest();
			int j = md.length;
			char[] ret = new char[j * 2];
			for (int i = 0, k = 0; i < j; i++) {
				byte byte0 = md[i];
				ret[k++] = hexDigits[byte0 >>> 4 & 0xf];
				ret[k++] = hexDigits[byte0 & 0xf];
			}
			return new String(ret);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * 先DES，再MD5
	 * 
	 * @param data
	 * @return
	 */
	public static final String encryptPwd(String data) {
		String desEncrypt = encryptDES(Constants.ENCRYPT_KEY, data);
		return encryptMD5(desEncrypt);
	}

}
